Sharp, full 3-stop IS, weather-sealed, convenient zoom range, one of very few (or is it the only one?) image-stabilized 24mm wide-angle lens, doesn't feel too heavy

Cons:

contrast could be a bit better

This is a very sharp lens, or supposed to be. At least, for me it became one after its trip to Canon. Now, when I examine the images from it, I continue to be surprised how sharp it is. Probably the best general purpose lens, and a unique wide-angle image-stabilized zoom.